Encrypted messages, fancy technology, spies use them all to communicate, but sometimes the best way to hide is in plain sight. Right now, broadcasting across the airwaves around the world, are automated, anonymous shortwave AM radio stations that most governments won't acknowledge even exist, much less explain. Best of all, you can hear recordings from them right now, and if you have the right gear, tune in and listen yourself.

Numbers Stations: Real Spy Broadcasts, On the Air Now

Numbers stations are anonymous, shortwave AM radio stations that broadcast messages at pre-set times, sometimes periodically and sometimes random, on specific frequencies. They're notable for their unusual tone and content, as the stations can be silent for most hours of the day or week, then jump to life with a collection of artificial human voices, sounds, Morse code, short songs, or even nursery rhymes. They also broadcast in a number of different languages. If you've ever listened to a numbers station, it's one of the creepiest things you've ever heard. You won't exactly use these to get more work done or streamline your life, but it's a lot of fun to listen.

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Another characteristic of numbers station broadcasts is the messages feel like gibberish, or nonsensical words, letters, or songs strung together. In reality, they likely mean a great deal to the right listener. Numbers stations appeared shortly after World War II, and while they were most plentiful during the Cold War, many still broadcast today. If you ask the FCC about them, they'll say they have no information on them because the frequencies are unlicensed. Ask any specific government agency and they'll usually deny they exist, or at least deny broadcasting on them. Who operates them and who are they for? Most likely they're used by spies, sending and listening for coded messages.

How Do These Stations Work?

The behavior of shortwave radio in the atmosphere makes it ideal for long range radio transmission. You can send messages on a given frequency all over the world, and most people who use shortwave radio use it to communicate with ships at sea and people in locations all over the world.

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You can see how they'd be ideal for spies: transmit a one-way message to someone anywhere in the world—literally thousands of miles away from the origin point—on an unlicensed station so no one knows who you are. Send them a code that can be deciphered using information only they know, or even a one-time pad that's never used again and changes from message to message. It's no wonder they're still in use today.

How Can I Listen to Numbers Stations?

The beauty of shortwave AM radio is that it's blasted through the air, free and clear. All you really need is a shortwave AM radio you can use to pick up the broadcasts, and an idea of when to listen. Even if you don't have one though, there are some ways you can get an idea what these secret messages sound like. Here's how:

That's all you'll really need. The site Spynumbers.com has an old—but still mostly accurate—list of numbers stations, recordings from them, and their known frequencies and times of broadcast. Numberstations.co.uk does as well, and the Global Frequency Database can help you learn more if you know a frequency already. (The HF Underground Spy Numbers logging forum also has up-to-date frequencies. Thanks for the tip, Chris!) If you have a commercial shortwave radio that can get those frequencies, just tune in.

To listen online: Listening in real time online is a trickier proposition, but it's still possible:

SDR Space is a community-run service of shortwave receivers operated by individuals around the globe that open up their servers to anyone running the SDR Radio (Software Defined Radio) client. If you have your own receiver, you can use SDR radio to connect it to your computer and tune, listen, and record broadcasts. If you live somewhere with no transmitter or where there's too much interference, you can connect to someone with a server, tune, and listen.

A number of shortwave enthusiast sites, like HFRadio.org and The Listening Post have shortwave tuners you can adjust and listen to in real time, online, anytime you want. The Listening Post even links to other web controlled radios around the world, so you can try your luck if you think you're getting interference or jamming. Your mileage may vary.

Grab your favorite online tuner or receiver, punch in the frequency (as long as it's supported) at the right time, and as long as your tuner isn't in an area with a lot of interference or noise, you can listen to the broadcasts as they happen.

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To listen to recordings: This is probably the safest way, or at least the way that won't creep you out when you've been listening to silence for a half-hour only to jump when you hear a lady's voice speaking in Czech singing a limerick, or a child repeating letters from the phonetic alphabet. Here are some options to get into numbers stations on your own time:

We mentioned Spynumbers.com before as a way to get frequencies and schedules of broadcasts, but they also have a database of recordings and links to other sites as well.

Numbers Stations walks you through the technology and history of Numbers Stations in greater detail than we can here, along with the methods of transmission and the devices used to broadcast the stations. At the end of the piece, you can listen to recordings of some of the most famous ones.

Hundreds of recordings, many made very recently, have also been uploaded to YouTube, including the entire Conet Project, including the videos here. Exercise caution though, numbers stations have urban legend status with some people (for example, it is not illegal to listen in to numbers stations), but at least you can hear some of the recordings and learn more about the stations at your leisure.

Once you've explored a few numbers station recordings or even tuned in to a few yourself, you'll never really look at the antenna array on the top of a building the same way again. Here in Washington DC, where I live, the airwaves are full of shortwave AM broadcasts in a variety of languages—some are just news and weather data being broadcast for foreign nationals and from antenna arrays on the tops of embassies, but others are...more curious. The best part is you never know where they're coming from and who's broadcasting them, but you know they're intended for someone, and they carry an important message.

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This post is part of Spy Week, a series at Lifehacker where we look at ways to improvise solutions to every day problems Bond-style. Want more? Check out our spy week tag page.